Incinerator

ABSTRACT

The present invention relates to a furnace for combustion of refuse, especially household and industrial refuse, and of the type comprising a horizontal chute with a transporting gate arranged longitudinally in said chute. The object of the invention is to provide a furnace of the above stated art which can be erected and installed easily and for lowcosts, and which also can be arranged in unused brick kilns, especially such of the Hoffmann-type. Another object of the invention is to provide a furnace in which complete combustion of the refuse is secured maintaining a relatively low-temperature under and in the grate itself, but maintaining a maximum temperature in a range of about 800* C. in order to remove odor from undesired odors in the flue gas. These and following objects are apparent from and are achieved with the following disclosure.

United States Patent [72] Inventor Kristian Pedersen Munk Kalundborg, Denmark [21] Appl. No. 19,446

[22] Filed Mar. 13, 1970 [45] Patented Dec. 7, 1971 [73] Assignee Keller Ofenbau G.m.b.l-l.

Carl-Keller-Strasse, Germany [54] INCINERATOR 4 Claims, 3 Drawing Figs.

[52] U.S. Cl 110/8 C, 1 10/40 R [51] Int. Cl F23g 5/12 [50] Field of Search 110/7, 8, 8 C, 15, 18, 18 C, 35,40

[56] References Cited UNITED STATES PATENTS I 2,752,869 7/1956 Keenan, Jr 110/15 X 3,469,544 9/1969 Kremer 110/35 3,473,493 10/1969 Simpson Primary Examiner- Kenneth W. Sprague Attorney-Polachek & Saulsbury llO/lSX ABSTRACT: The present invention relates to a furnace for combustion of refuse, especially household and industrial refuse, and of the type comprising a horizontal chute with a transporting gate arranged longitudinally in said chute.

The object of the invention is to provide a furnace of the above stated art which can be erected and installed easily and for low-costs, and which also can be arranged in unused brick kilns, especially such of the Hoffmann-type. Another object of the invention is to provide a furnace in which complete combustion of the refuse is secured maintaining a relatively low temperature under and in the grate itself, but maintaining a maximum temperature in a range of about 800 C. in order to remove odor from undesired odors in the flue gas.

These and following objects are apparent from and are achieved with the following disclosure.

PATENTEUDEB H97! 3525451 sum 1 OF 3 INVENTOR KRISTIAN PEDERSEN MUNK PATENTEUOEB nan 31526461 SHEET 2 OF 3 Fig.2

' INVENTOR KRISTIAN PEDERSEN MUNK TTDRNE Y5 PATENTED DEB 71971 SHEET 3 BF 3 Q //M////////////////// a N KKKK Nw L m r INVENTOR KRISTIAN PEDERSEN MUNK INCINERATOR According to the invention the grate is a traveling grate with bars arranged crosswise to the transport direction of the grate, the grate being arranged in the main horizontally from the feed end to the dispose end of the furnace, the combustion material carrying parts of the grate in vertical longitudinal section showing scallops or .prongs with inclined up-running stretches, separated by steep down-running stretches, the fresh air being, as known per se, introduced by the dispose ends of the furnace below the grate and the flue gas departing from the feed end of the furnace, auxiliary fuel burners for supporting the combustion being arranged in suitable places in the top of the chute.

The refuse to be combusted is introduced in the top of the chute in a manner known per se and falls down upon the moving grate. Resting upon the grate the combustible material meets the hot gas from the dispose ends of the furnace and is heated so that moisture will evaporate. Traveling further upon the grate the material begins to burn, and whenever the material is moved to the top of the upwards inclined stretches of the grate the material will be tipped over and fall down to the bottom of the next upward inclined stretch. in this way the material will be turned over several times during its way through the incinerator, whereby the complete incineration of all of the combustible refuse material is secured.

The invention is further, disclosed by reference to the drawing wherein FIG. 1 shows an embodiment of a furnace according to the invention in perspective view with parts of the one sidewall and the end walls of the chute removed,

FlG. 2 a cross section of the chute and FIG. 3 a side view of FIG. 2.

In the attached drawings, 1 is a chute of bricks lined with a refractory material. in the lower part of the chute the traveling grate S is mounted between two rotating members 2 and 2" arranged horizontally and crosswise to the longitudinal direction of the chute. Between the two members 2 and 2" several sets of other rotating members 3' and 3 are arranged so that the grate from the rotating member 2' to the rotating member 3 travels upwards a stretch marked 6 and then steeply downwards as marked by 7 to the rotating member 3" and then upwards to the next rotating member 3' and so on. The grate is composed by bars extending from one side of the chute to the other, in both sides leaving a space between the end of the bar and the chute wall.

The rotating member 2' is driven in direction against the clock by a shaft 8 which through a reduction gear box 9 is driven by an electrical motor. In the top of the chute at its feed end a hopper 10 is provided. Eleven is an elevating conveyor transporting collected refuse, for instance in paper sacks as shown, from the collecting station to the hopper. The bottom of the hopper is closed by a lock-arrangement allowing the refuse with intervals to fall down upon the grate without escape of flue gas through the hopper. The spaces between the grate bar ends and the chute wall are covered with protecting screens. The lower edges of the protection screens 13 follow the run of the grate leaving a narrow space between the free surface of the grate stretches 6 respectively 7 open for air entrance. At the end of the traveling grate under rotating member 2" a conveyor 12 extends sideways through the chute wall, this conveyor receives the incinerated refuse which has not been combusted in the chute. This end, i.e. the dispose end of the chute is closed by a wall, and behind this wall a fan 14 is installed. This fan 14 takes in fresh air which is then forced into the chute through two ducts 15 leading the air to inlets l6 placed under the grate 5 under the level in which the grate travels from rotating member 2" to rotating member 2.

At the feed end of the chute a wall 17 is erected so that this end of the chute is covered by a massive wall 17 erected from the bottom of the chute and covering from one-half to twothirds of the chute crosssection. The rest of the chute cross section is covered by a wall part 18 having openings for the ,flue gas. This part of the chute is connected to a chamber for collecting. fly ash carried by the flue gas streaming out from the chute above the massive wall 17. (Collecting chamber not shown.) From the fly ash collecting chamber the flue gas is directed to ,a chimney. If desired a heat exchanger may be installed between the fly ash collecting chamber and the chimney.

In the top of the chute three burner units 19 for instance oil burner units are arranged with burner heads 20 extending downwards into the chute.

As more detailed shown in FIGS. 2 and 3 each of the grate bars may carry upstanding wings 21. These wings are mounted so that the wing ofone bar is staggered relatively to the wings of the neighbor bars. Preferably, each of the bars is provided with dogs 22. In the embodiment shown in the drawings the grate bar is carried on chain links which again are carried by chain wheels 3' and 3" rotatably mounted upon gudgions. These gudgions are arranged in the space formed between the protection plate 13 and the corresponding chute wall. In order to protect the chain links and the grudgions against the heat from the combustion in the chute, the protection plate 13 is covered with a layer of heat insulating and heat resistant material on the sides facing the chute wall.

The working of the furnace is as follows:

Refuse is transported by means of the conveyor 11 to the hopper 10 and with intervals the locking device of the hopper is loosened so that refuse drops down on the first upwards going stretch 6 of the traveling grate 5. There the refuse is met by air and flue gas streaming through the chute in direction towards the at least partly open end wall l7, l8. Thereby, the refuse is partly dried, and if any part of the refuse resting directly upon the grate bars still contains moisture when the refuse passes the highest part of the stretch 6, these parts will be exposed to the streaming air-gas when the refuse is turned over by the falling down to the next upwardly inclined stretch 6. When the refuse is sufficiently dried, the material begins to burn, and due to the fact that the material is several times turned over when parting from one stretch 6 to the next stretch 6, all parts of the refuse are successively exposed to air nourishing combustion. The air necessary for this purpose is introduced by the fan 14 through the ducts 15 to the inlets 16. From these inlets the air is distributed along each of the spaces between the chute wall and the protection plate 13 and also to the space between the upper grate traveling in direction to the dispose end of the furnace and the grate parts returning to the feed end of the furnace.

The grate may be arranged with only a narrow space between neighbor bars, and thus most of the air will pass up over the wings 21, down again between these wings and the space or slit of the protection plate 13 and sideways through the space between the lower part of the protection plates 13 and the upper surface of the bars 4 of the upper part of the grate. Only a minor part of the air will pass up between the small space between neighbor bars.

It has been found that the temperature of the gas for carrying the combustible refuse may be kept between 400 and 500 C. If the heat developed in the last half of the furnace is not sufflciently high to ignite the combustible material in the first half of the furnace, one or more of the oil burners 19, 20 may be started. The sideways introduction of air to nourish the combustion in connection with the repeated turnover of the material resting upon the grate results in a complete incineration of the refuse.

It has been found that a furnace according to the invention and having a size of length 10 meters and width 1.6 meters is able to incinerate 2.500 kilos household refuse of average quality per hour.

Most of the ash formed by the incineration has been either separated in the fly ash collecting chamber or has been found as coarse ash among uncornbustible material led out from the furnace by the conveyor 12, whereas only very small amounts of ash have been falling through the grate bars to the bottom of the chute.

Various details by the furnace in question may be designed and described in other ways, and the feed end andthe dispose end may be arranged otherwise than shown. The way in which the grate is arranged over the various rotating members may also be varied. Thus the rotating members 2' and 2 may be rollers or may be chain wheels arranged in any desired way. The same relates to the rotating members 3 and 3 What 1 claim is: conveyor 1 l 1. A furnace for combustion of refuse, especially household and industrial refuse, comprising a horizontal chute, a transporting grate arranged longitudinally, within said chute, the grate being a traveling grate, said grate including grate bars arranged crosswise to the transport direction of the grate, the grate having a feed end and a dispose end at opposite ends of said grates imaginary longitudinal axis, said grate being arranged in the main horizontally from the feed end to the dispose end of the furnace, said grate including combustion material-carrying parts which in vertical longitudinal section show a series of interconnected consecutive scallop means in which each scallop means includes a first inclined up-running stretch and a second steep down-running stretch separating consecutive ones of said first stretch, fresh air being introduceable at the dispose end of the furnace below the grate and flue gas being departable from the feed end of the furnace, and auxiliary fuel burners for supporting the Combustion being arranged operatively in the chutes top.

2. Furnace according to claim 1, characterized in that the bars rest upon endless chains, which at the ends of the furnace run upon chain wheels sets and that these chains on their way from the first wheel set to the second wheel set are guided by a number of third and fourth wheel sets, the wheels of the third set being arranged in a higher level than the wheels of the fourth set.

3. Furnace according to claim 2, characterized in that the bars at their ends carry upstanding wings, the wing of one bar being preferably staggered relatively to the upstanding wings of neighbor bars.

4. Furnace according to claim 3, characterized in protection plates extending downwards from each of the sidewalls of the chute and to the grate part which carries the combustible material, leaving a narrow air space open both between the edge of the protection plate and the grate and between the lower side of the protection plates and the sides of the wings. 

1. A furnace for combustion of refuse, especially household and industrial refuse, comprising a horizontal chute, a transporting grate arranged longitudinally, within said chute, the grate being a traveling grate, said grate including grate bars arranged crosswise to the transport direction of the grate, the grate having a feed end and a dispose end at opposite ends of said grate''s imaginary longitudinal axis, said grate being arranged in the main horizontally from the feed end to the dispose end of the furnace, said grate including combustion material-carrying parts which in vertical longitudinal section show a series of interconnected consecutive scallop means in which each scallop means includes a first inclined up-running stretch and a second steep down-running stretch separating consecutive ones of said first stretch, fresh air being introduceable at the dispose end of the furnace below the grate and flue gas being departable from the feed end of the furnace, and auxiliary fuel burners for supporting the combustion being arranged operatively in the chute''s top.
 2. Furnace according to claim 1, characterized in that the bars rest upon endless chains, which at the ends of the furnace run upon chain wheels sets and that these chains on their way from the first wheel set to the second wheel set are guided by a number of third and fourth wheel sets, the wheels of the third set being arranged in a higher level than the wheels of the fourth set.
 3. Furnace according to claim 2, characterized in that the bars at their ends carry upstanding wings, the wing of one bar being preferably staggered relatively to the upstanding wings of neighbor bars.
 4. Furnace according to claim 3, characterized in protection plates extEnding downwards from each of the sidewalls of the chute and to the grate part which carries the combustible material, leaving a narrow air space open both between the edge of the protection plate and the grate and between the lower side of the protection plates and the sides of the wings. 